Immunohistochemical staining of testicular tissue samples from mouse, monkey and human was carried out as described previously (Mayer et al. 2016 (link)). For each species a minimum of four and up to 14 different sections were examined. Polyclonal rabbit anti-NLRP3 IgG (R30750, NSJ Bioreagents, San Diego, CA, USA) was used as primary antibody to stain for NLRP3. Negative controls consisted of omission of the primary antibody, of incubation with rabbit IgG or non-immune serum instead of the primary antiserum. Sections were counterstained with hematoxylin and visualized using a Leica DM2500 microscope equipped with a DMC2900 CMOS camera or an Zeiss Axiovert microscope with an Insight Camera (18.2 Color Mosaik) and Spot advanced software 4.6 (SPOT Imaging Solutions, Sterling Heights, MI, USA).